.page-about {
  --about-rail: 232px;
  --about-gap: clamp(28px, 5vw, 64px);
}

.page-about .crumbs {
  padding-top: 18px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding: clamp(26px, 5vw, 60px) 0 clamp(34px, 6vw, 74px);
  border-bottom: 1px solid var(--line);
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(30px, 6vw, 56px);
  align-items: start;
}

.page-about h1 {
  font-family: var(--ff-display);
  font-weight: 900;
  font-size: var(--fs-h1);
  line-height: 1.14;
  letter-spacing: -0.01em;
  color: var(--white);
  margin: 14px 0 0;
  max-width: 20ch;
}

.page-about .about-hero__lede {
  margin-top: 20px;
  font-size: var(--fs-body);
  line-height: 1.78;
  color: var(--stone);
  max-width: 60ch;
}

.page-about .about-hero__acts {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.page-about .about-hero__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .stat {
  background: var(--ink);
  padding: 18px 16px 20px;
}

.page-about .stat__head {
  display: flex;
  align-items: baseline;
  gap: 6px;
  margin: 0;
}

.page-about .stat__num {
  font-family: var(--ff-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  font-size: clamp(26px, 3.6vw, 34px);
  line-height: 1;
  color: var(--green);
}

.page-about .stat__unit {
  font-family: var(--ff-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--mist);
}

.page-about .stat__label {
  margin: 10px 0 0;
  font-size: 13px;
  line-height: 1.55;
  color: var(--mist);
}

/* ---------- 双栏骨架 ---------- */
.page-about .about-layout {
  display: grid;
  gap: var(--about-gap);
  padding: clamp(38px, 6vw, 78px) 0 clamp(48px, 7vw, 96px);
}

.page-about .about-rail {
  border-top: 2px solid var(--green);
  padding-top: 16px;
}

.page-about .about-rail__cap {
  color: var(--mist);
  margin: 0 0 12px;
}

.page-about .about-rail__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 2px;
}

.page-about .about-rail__list a {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 9px 10px;
  font-size: 14px;
  line-height: 1.4;
  color: var(--stone);
  text-decoration: none;
  border-left: 2px solid transparent;
  transition: color 0.22s var(--ease), border-color 0.22s var(--ease), background-color 0.22s var(--ease);
}

.page-about .about-rail__list a:hover,
.page-about .about-rail__list a:focus-visible {
  color: var(--white);
  border-left-color: var(--green);
  background: var(--ink-2);
}

.page-about .about-rail__list .idx {
  color: var(--mist);
  flex: none;
}

/* ---------- 连续章节 ---------- */
.page-about .about-body {
  min-width: 0;
}

.page-about .about-sec {
  padding: clamp(28px, 4vw, 44px) 0;
  border-top: 1px solid var(--line);
}

.page-about .about-sec:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .about-sec:last-child {
  padding-bottom: 0;
}

.page-about .about-sec h2 {
  font-family: var(--ff-display);
  font-weight: 800;
  font-size: var(--fs-h2);
  line-height: 1.22;
  color: var(--white);
  margin: 12px 0 0;
  max-width: 26ch;
}

.page-about .about-sec p {
  margin: 16px 0 0;
  font-size: var(--fs-body);
  line-height: 1.78;
  color: var(--stone);
  max-width: 66ch;
}

.page-about .about-sec a {
  color: var(--green);
  text-decoration: none;
  border-bottom: 1px solid rgba(43, 240, 138, 0.4);
}

.page-about .about-sec a:hover {
  border-bottom-color: var(--green);
}

.page-about figure {
  margin: 0;
}

.page-about figure img {
  width: 100%;
  max-width: 100%;
  height: auto;
  display: block;
  object-fit: cover;
}

.page-about .about-tl-fig {
  margin-top: 26px;
}

.page-about .about-sec--split {
  display: grid;
  gap: clamp(24px, 4vw, 46px);
}

.page-about .about-sec--split figure {
  margin-top: 0;
}

/* ---------- 时间线 ---------- */
.page-about .tl {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
}

.page-about .tl__item {
  border-top: 1px solid var(--line);
}

.page-about .tl__item:last-child {
  border-bottom: 1px solid var(--line);
}

.page-about .tl__more summary {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px 14px;
  padding: 16px 0;
  cursor: pointer;
  list-style: none;
  transition: color 0.22s var(--ease);
}

.page-about .tl__more summary::-webkit-details-marker {
  display: none;
}

.page-about .tl__more summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--ff-mono);
  font-size: 18px;
  line-height: 1;
  color: var(--mist);
}

.page-about .tl__more[open] summary::after {
  content: "−";
  color: var(--green);
}

.page-about .tl__more summary:hover .tl__title,
.page-about .tl__more summary:focus-visible .tl__title {
  color: var(--green);
}

.page-about .tl__year {
  font-family: var(--ff-mono);
  font-variant-numeric: tabular-nums;
  font-size: 20px;
  font-weight: 700;
  min-width: 4ch;
  color: var(--green);
}

.page-about .tl__ver {
  font-family: var(--ff-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--mist);
  padding: 2px 7px;
  border: 1px solid var(--line-2);
}

.page-about .tl__title {
  flex: 1 1 14ch;
  font-size: 16px;
  font-weight: 600;
  color: var(--white);
  line-height: 1.5;
  transition: color 0.22s var(--ease);
}

.page-about .tl__body {
  padding: 0 0 18px;
}

.page-about .tl__body p {
  margin: 0;
  font-size: 15px;
  max-width: 62ch;
}

/* ---------- 三段更新流程 ---------- */
.page-about .flow {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  gap: 18px;
  counter-reset: flowstep;
}

.page-about .flow li {
  position: relative;
  padding-left: 44px;
  counter-increment: flowstep;
  font-size: var(--fs-body);
  line-height: 1.72;
  color: var(--stone);
  max-width: 64ch;
}

.page-about .flow li::before {
  content: "0" counter(flowstep);
  position: absolute;
  left: 0;
  top: 3px;
  font-family: var(--ff-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--green);
}

.page-about .flow strong {
  display: block;
  font-weight: 600;
  font-size: 15px;
  color: var(--white);
  margin-bottom: 4px;
}

/* ---------- 团队四组 ---------- */
.page-about .team-list {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.page-about .team-list li {
  background: var(--ink);
  padding: 14px 4px 14px 16px;
  font-size: 15px;
  line-height: 1.68;
  color: var(--stone);
}

.page-about .team-list__role {
  display: block;
  font-family: var(--ff-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--green);
  margin-bottom: 6px;
}

/* ---------- 合作与资质 ---------- */
.page-about .partner-list {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .partner-list li {
  padding-top: 14px;
  border-top: 1px solid var(--line);
  font-size: 15px;
  line-height: 1.7;
  color: var(--stone);
}

.page-about .badge-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 22px;
}

.page-about .badge-row span {
  font-family: var(--ff-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--green);
  background: var(--green-deep);
  padding: 8px 12px;
}

/* ---------- 联系条 ---------- */
.page-about .contact-strip {
  margin-top: 26px;
  padding: 20px 22px;
  background: var(--ink-2);
  border-left: 2px solid var(--green);
  max-width: 62ch;
}

.page-about .contact-strip p {
  margin: 0;
}

.page-about .contact-strip__line {
  font-family: var(--ff-mono);
  font-variant-numeric: tabular-nums;
  font-size: 15px;
  line-height: 1.9;
  color: var(--white);
  word-break: break-word;
}

.page-about .contact-strip__line .idx {
  display: block;
  color: var(--mist);
  margin-bottom: 2px;
}

.page-about .contact-strip__note {
  margin-top: 10px;
  font-size: 13px;
  color: var(--mist);
}

/* ---------- 收尾 ---------- */
.page-about .about-cta {
  margin-top: clamp(48px, 7vw, 92px);
  padding: clamp(36px, 6vw, 72px) 0;
  background: var(--ink-2);
  border-top: 1px solid var(--line);
}

.page-about .about-cta__grid {
  display: grid;
  gap: 26px;
  align-items: center;
}

.page-about .about-cta__cap {
  color: var(--mist);
  margin: 0;
}

.page-about .about-cta h2 {
  font-family: var(--ff-display);
  font-weight: 800;
  font-size: var(--fs-h2);
  line-height: 1.2;
  color: var(--white);
  margin: 10px 0 0;
  max-width: 24ch;
}

.page-about .about-cta p {
  margin: 14px 0 0;
  font-size: var(--fs-body);
  line-height: 1.74;
  color: var(--stone);
  max-width: 56ch;
}

.page-about .about-cta__acts {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-rail__list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 860px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.5fr) minmax(0, 0.9fr);
  }

  .page-about .about-sec--split {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  }

  .page-about .about-cta__grid {
    grid-template-columns: minmax(0, 1fr) auto;
  }
}

@media (min-width: 1000px) {
  .page-about .about-layout {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
  }

  .page-about .about-rail {
    position: sticky;
    top: calc(var(--head-h) + 24px);
    align-self: start;
  }

  .page-about .about-rail__list {
    grid-template-columns: 1fr;
  }

  .page-about .about-hero__stats {
    grid-template-columns: 1fr;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-rail__list a,
  .page-about .tl__more summary,
  .page-about .tl__title {
    transition: none;
  }
}
<<<END>>>